by Greg LaBarge, Fulton County
June 2 update. Peter Thomison has put together a chart for Ohio with dates and Crop Relative Maturity (CRM) targets. Which is found to the left. An article accompanying this information can be found at http://corn.osu.edu/newsletters/2011/corn-2011-16/more-on-switching-hybrid-maturities
What do we do about corn maturities as we finish off the late planting season is a common question today and Dr Bob Nielson has provided a chart for Indianan we can adapt to our NW Ohio area. The table has two different goals that affect the maturity we plant based on June planting. A target of reaching physiological maturity by first frost and one week prior to first frost is highlighted in the table below. You can see Dr Nielsen’s entire article at http://www.agry.purdue.edu/ext/corn/news/articles.11/SafeHybridMaturities-0517.html
For NW Ohio the far west counties have a frost of October 10, for the rest of the area we have a date that is basically October 15th. This gives us a bit more cushion than the chart below which shows a frost date of October 6th for Indiana.
One other cultural practice that we need to consider related to harvest maturity is use of starter nitrogen. As we get later, it maybe tempting to skip the starter step to save time. While it is true the yield benefits may not be there, some research has shown it maybe a benefit to keep 20-40 pound of N starter in the mix when we talk about fall maturity.
Table 1 Approximate Safe Maturity Dates for Indiana to reach stated goal prior to 50% chance frost date.
|Goal||Indiana District||Typical Corn Relative Maturity||Expected Fall frost date||30-May||10-Jun||20-Jun|
|Physiological Maturity by week of frost||NE||109||6-Oct||106||103||98|
|Physiological Maturity one week before expected frost||NE||109||6-Oct||104||100||95|
|Recommendations from Dr. Bob Nielson, Purdue University|